Recently, I found that my nacelle exhaust fairings were deteriorating in my 1963 Twin Comanche. Replacements are no longer available. I found a solution through Knots2u . They sell a stainless steel kit that installs right over the top of the existing nacelles. It requires a lot of work drilling out all of the rivets and then re-riveting them, removing then reinstalling exhaust pipes and oil breather lines and cutting the ends of the exhaust pipes at an angle.

Once complete, I now have much better nacelles that are easier to clean and will not wear out.